This invention relates to a pneumatic reel fiber pay out system which pulls a fiber or filament from a stationary bobbin and winds it onto a non-rotating spool by using high speed gas or fluid flow to generate a drag force on the fiber or filament.
More particularly the invention relates to apparatus from pneumatically pulling and winding an optical filament onto a non-rotating spool from a stationary supply bobbin. The invention includes guide means to guide the optical filament into a fluid stream which is created by a stationary means and driven at a supersonic speeds around the non-rotating spool. This stream acts as a fluid guide to wind the filament or fiber onto the surface of the non-rotating spool.
Missile systems such as the fiber optic guided missile (FOG-M) use fiber optic data links for communication between the missile and the gunners station during flight. Typically these systems contain a tapered cylindrical bobbin of filament carried by the missile which is payed out from the rear of the missile during its flight. In order to economically test a variety of bobbin fiber concepts or configurations, and to better understand the physics of the fiber pay out, a method for ground testing such bobbins is required.
Typical test methods have consisted of mounting a supply bobbin on an instrumented test stand and using a device to pull the fiber or filament from the bobbin. Such systems currently available include a pneumatic shoe and a pinch wheel. The pneumatic shoe pay out system uses a high speed rotating disk to pull the fiber or filament from the test bobbin. When the disk reaches the desired speed, gas is blown through orfices in the pneumatic shoe which forces the filament onto the rotating disk. Friction between the filament and the disk causes the filament to be pulled from the stationary supply bobbin and thrown downstream of the pneumatic shoe.
The pinch wheel pay out system, on the other hand, uses two driven disks to nip the filament and to pull it from the test bobbin. Each of these disks is coated with a high friction material on the surface which contacts the filament. When the two disks reach the desired surface speed they are closed together to nip or pinch the filament. This pulls the filament from the stationary bobbin and throws it downstream of the pinch wheel nipping device.
These two pay out devices or systems do not provide for an orderly collection of the filament after its pay out nor do they allow for the transmission of signals through the filament during the pay out itself. Transmission of signals through the filament is very desirable in such test devices because it allows the determination of the attenuation caused by the filament stresses induced during the pay out test. In addition, if the filament is collected in a orderly manner, attentuation, due to the high stresses induced by the collection device will be reduced. Each of the prior art systems also requires the use of high speed rotating parts which reduces the reliability of the devices and increases their maintenance cost.